CAREER: Tackling the Solvent-Stabilizer Co-contamination by Propanotrophic Bacteria with Catalytically Versatile Di-iron Monooxygenases

Thousands of aquifers are contaminated with mixtures of chlorinated aliphatic hydrocarbon (CAH) solvents and stabilizers like 1,4-dioxane. To date, there is no single remediation strategy capable of treating both types of pollutants simultaneously. To tackle the problem, an innovative biological treatment will be developed that employs bacteria growing on propane that are capable of simultaneously degrading both CAHs and 1,4-dioxane. Development of this approach requires the isolation of a diverse collection of bacterial strains capable of effective treatment under various field conditions. This novel remediation strategy is potentially transformative in its precision targeting for specific contaminated sites. An added benefit of this approach results from it being less disruptive to the environment compared to other available remedial strategies. Through laboratory experimentation and hands-on training with stakeholders, the investigator will develop the next generation of environmental remediation professionals. Recruitment of students from diverse backgrounds will broaden participation in these fields.<br/><br/>Bioremediation is frequently a preferred groundwater contamination treatment method because it uses a natural approach to degrade pollutants at relatively low cost. However, the success of this approach is highly dependent on the specific physiochemical characteristics and the indigenous microbiota of a given site, resulting in site-specific solutions with narrow applicability. To increase the effectiveness of bioremediation, the PI will establish a collection of propanotrophic isolates and consortia exhibiting robust degradation capabilities and environmental adaptabilities. This strategy relies on the synergy of conventional cultivation approaches and state-of-the-art biotechnologies such as metagenomics and single-cell genomic analysis to advance understanding of cometabolic biodegradation at the molecular, cellular, and microbial community levels. This research focuses on propane-inducible soluble di-iron monooxygenases (SDIMOs) as versatile biocatalysts, uniquely capable of degrading a variety of chlorinated solvents and 1,4-dioxane. Novel SDIMOs will be identified and their catalytic capacities and kinetics will be characterized in heterologous expression clones and knockout mutants. These insights will be used to refine the categories of SDIMOs to enable the design and interpretation of omics and other molecular biological tools to exploit the metabolic interactions among propanotrophic consortia obtained from different polluted habitats. Finally, bench-scale microcosm assays will be used to evaluate and compare the feasibility and reliability of conventional and diagnosis-based bioremediation strategies to advance their in situ applications. This research will be actively integrated with a core educational goal to cultivate the next generation of remediation professionals needed to address growing demand in the historically polluted New York-New Jersey-Connecticut tristate area. Taking advantage of the sizeable remediation industry in this area, the PI will engage students of all levels with a diverse range of on- and off-campus activities, such as guest lectures with environmental experts, professional workshops with alumni in the field, and University-sponsored research projects, as well as internships and networking opportunities with private and non-profit remediation organizations in the region. These experiences will give students critical access to applied research and training in the field, and foster long-lasting connections that are key catalysts for career success. Further, the PI will attract motivated students from underrepresented groups at two-year colleges and local high schools to take part in scientific seminars, laboratory tours, and part-time research opportunities.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.